1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
function toggleEnabled(event) {
if (!document.body)
return;
if (document.body.hasAttribute('show-alt'))
document.body.removeAttribute('show-alt');
else
document.body.setAttribute('show-alt', '');
}
function processImage(image) {
image.style.setProperty('min-height', image.height + 'px');
image.style.setProperty('min-width', image.width + 'px');
var style = window.getComputedStyle(image, null);
var contrastRatio =
axs.utils.getContrastRatioForElementWithComputedStyle(style, image);
if (contrastRatio != null && axs.utils.isLowContrast(contrastRatio, style)) {
var bgColor = axs.utils.getBgColor(style, image);
var fgColor = axs.utils.getFgColor(style, image, bgColor);
var suggestedColors = axs.utils.suggestColors(
bgColor, fgColor, contrastRatio, style);
var suggestedColorsAA = suggestedColors['AA'];
image.style.setProperty('color', suggestedColorsAA['fg']);
image.style.setProperty(
'background-color', suggestedColorsAA['bg'], 'important');
}
if (!image.hasAttribute('alt')) {
if (image.hasAttribute('_repaired'))
return;
var filename = image.src.split('/').pop();
image.setAttribute('_repaired', filename);
}
}
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(mutation) {
if (!mutation.addedNodes || mutation.addedNodes.length == 0)
return;
for (var i = 0; i < mutation.addedNodes.length; i++) {
var addedNode = mutation.addedNodes[i];
if (!(addedNode instanceof
addedNode.ownerDocument.defaultView.HTMLImageElement)) {
continue;
}
processImage(addedNode);
}
});
});
observer.observe(document, { childList: true, subtree: true });
var images = document.querySelectorAll('img');
for (var i = 0; i < images.length; i++) {
processImage(images[i]);
}
if (!infobarDismissed)
var infobarDismissed = false;
function createInfobar() {
if (infobarDismissed)
return;
if (!document.body)
return;
if (document.querySelector('.show-alt-infobar'))
return;
var showAltInfobar = document.createElement('div');
showAltInfobar.className = 'show-alt-infobar';
var showAltInfoControls = document.createElement('div');
showAltInfoControls.className = 'controls';
var showAltInfoCloseButton = document.createElement('button');
showAltInfoCloseButton.className = 'close-button-gray';
showAltInfoCloseButton.addEventListener('click', function() {
document.body.removeChild(showAltInfobar);
infobarDismissed = true;
});
showAltInfoControls.appendChild(showAltInfoCloseButton);
showAltInfobar.appendChild(showAltInfoControls);
var showAltInfoContent = document.createElement('div');
showAltInfoContent.className = 'content';
var showAltInfoText = document.createElement('span');
showAltInfoText.textContent = chrome.i18n.getMessage('alt_infobar');
showAltInfoText.setAttribute('role', 'status');
showAltInfoContent.appendChild(showAltInfoText);
var undoButton = document.createElement('button');
undoButton.className = 'link-button';
undoButton.textContent = chrome.i18n.getMessage('alt_undo');
undoButton.addEventListener('click', toggleEnabled);
var closeButton = document.createElement('button');
showAltInfoContent.appendChild(undoButton);
showAltInfobar.appendChild(showAltInfoContent);
document.body.insertBefore(showAltInfobar, document.body.firstChild);
}
|
